1. Field of Invention
The present invention relates to a light source device used for a projector, and particularly a light source device where a light source is operated by alternating current.
2. Description of Related Art
As projector devices, a liquid crystal projector device and a DLP (Trademark by Texas Instruments) projector device are available. A high-pressure mercury lamp is used as a projection light source that is used in these projector devices. A combination of the high-pressure mercury lamp and a reflecting mirror is a light source device, and this light source device is incorporated into the projector device at the point of use.
FIG. 15 shows a conventional light source device 1 described in Japanese Laid-Open Patent Application No. 2007-066742 and which is a cross sectional view along a pair of opposing electrodes 521 and 522 of a high-pressure mercury lamp 5. The light source device 1 includes a reflecting mirror 2 having a concave reflecting surface 211, and the high-pressure mercury lamp 5 arranged so as to match the center between the electrodes 521, 522 with a first focal point of the reflecting surface 211.
The reflecting mirror 2 includes a reflecting part 21 having the reflecting surface 211 and a cylinder neck part 22. An opening 23 is provided in the reflecting part 22 for accommodating a feed wire 552, as further described. A tubular base member 3 makes contact with the end of the neck part 22 of the reflecting mirror 2, and an insertion opening 31 in the base member 3 is arranged in an insertion opening 24 of the neck part 22. A light exit plate 4 is arranged in an opening of the reflecting mirror 2 and so as to emit reflected light from the reflecting surface 211 of the reflecting mirror 2.
The high-pressure mercury lamp 5 includes a discharge tube 51 having a roughly spherical light-emitting part 511 and hermetically sealed parts 512 and 513 extending from ends of the light-emitting part 511. The electrodes 521 and 522 are included in the light-emitting part 511, with external leads 541 and 542 protruding from the hermetically sealed parts 512, 513, respectively, and with foils 53 that electrically connect the electrodes 521 and 522 with the external leads 541 and 542, respectively and that is embedded in the hermetically sealed parts 512, 513, respectively. The ends of the pair of electrodes 521 and 522 are arranged within the light-emitting tube 511 so as to oppose each other, and mercury is included as light-emitting metal.
The first hermetically sealed part 512 of the high-pressure mercury lamp 5 is inserted into the successive insertion openings 24 and 31 of the reflecting mirror 2 and the base member 3, and an adhesive 61 fills the space between the base member 3 and the first hermetically sealed part 512, so as to adhere the first hermetically sealed part 512 and the base member 3. In this way, the high-pressure mercury lamp 5 is secured to the reflecting mirror 2, and the second hermetically sealed part 513 is arranged so as to extend toward the light exit plate 4. The external lead 542 protrudes from the second hermetically sealed part 513, with the feed wire 552 connected to the external lead 542 and leading to the outside of the reflecting mirror 2 through the opening 23 of the reflecting part 21.